Hello all I have recently replaced the head gaskets on my 2003 impreza sti type uk and now it has a miss fire , on closer inspection I have noticed the timing is a tooth out , and now I can't seem to get the marks right they line up perfect but then when I turn it over by hand it ends up out

 

The tension changes on the belt if you don't use the special tool to hold the cams in place. The only way that I'm managed to do it is to compensate for the move, and turn the engine (clockwise) 4 rotations to check that the marks still line up correctly.
If it helps, I've always found it easier to set up the belt on pistons 1 & 3 (drivers side) before putting the belt on the cam pulleys for 2 + 4.
Hope this helps.

 

I don't think the lines will relign up once you rotate the engine. You would have to turn the engine over by hand many times to make them line up again.
The lines will walk forward a bit with each rotation.

 

The lines on the belt won't line up again, but all the pulleys should line up with their timing marks.

 

check the teeth on the bottom crank sprocket if you have a tooth that's got a chip on it this can cause a missfire and hard to start up ive had this problem myself.hope this helps

 

I shall investigate this morning